Something I will (probably) not repeat

On hindsight, there were many idiotic actions which I did in the past. There is one which I think will not happen again, but that is something which I am not 100% sure.
One incidence occurred when I was a student nurse at St Bernard's Wing. It happened in 1983. I arrived one hour late because I kept thinking the clock had changed. I really felt silly because I arrived in the UK in 1977. I guess it was my ego which stopped me from double checking.
Have you made a similar mistake?
Do you think that you will not be repeating any idiotic acts?
Any other thoughts on this matter?